Identification of novel genes involved in FT function or transport

Flowering of Arabidopsis is influenced by seasonal changes in day length, so that plants flower early in long days of summer and late under short days of winter. In Arabidopsis, FloWErinG loCUs t (Ft) is a component of the photoperiodic pathway and its transcription is activated under long days. FT protein is expressed in the leaf vascular tissue and then moves through the phloem to the shoot apex, where it causes changes in gene expression that reprogram the shoot apical meristem to form flowers instead of leaves. Recent studiesdemonstrated that the Ft homolog tsF also participates in the photoperiodic flowering pathway redundantly with FT. To deepen our knowledge of the function and transport of FT, we performed different genetic and genomic approaches. First, we have generated a mutant collection from the ft tsf double mutant, which is insensitive to day length and very late flowering under long days, and from GAs1: Ft ft tsf plants which are early flowering. We have already identified many early and late flowering mutants in both genetic backgrounds.The genes affected in the most promising mutants will be identified using Illumina next generation sequencing. Second, we investigated the global effects of FT on gene expression in leaves by studying which genes are specifically affected by FT and/or TSF by comparing Col-0 with ft tsf and GAs1:Ft tsf ft genotypes. Our Tiling Array experiment showed that several differentially expressed genes affected by FT in leaves encode proteins which potentially can modify cellular membranes. Further studies are being performed in order to test thecontribution of these candidate genes to FT function or transport.